German patent application DE 10 2007 043 670 A1 discloses an agitator ball mill with a cylindrical grinding container, wherein an agitator shaft connected to a drive is disposed in the grinding container. The agitator shaft transmits a part of the drive energy to the auxiliary grinding bodies which are disposed loosely in the grinding container. A helical separating device is disposed in front of the grinding stock outlet.
European patent application EP 1 468 739 A1 discloses a continuously operating horizontal agitator ball mill used for the fine and ultrafine grinding of a material, said agitator ball mill comprising a cylindrical or conical grinding chamber for receiving grinding bodies. A stock inlet emerging into the interior of the grinding chamber is disposed at one end of the grinding chamber. A stock outlet leading out of the interior space is located at the other end of the grinding chamber. Furthermore, an agitator coaxial with the chamber axis and comprising a plurality of agitator elements is present. Disposed in front of the stock exit is a separately driven separation system, which separates the grinding bodies from the ground stock and conveys them back into the interior of the grinding chamber. The separation system is formed by a separating element, which comprises two circular discs disposed coaxial with the chamber axis. A plurality of conveying or blade elements, which are distributed symmetrically around the centre-point of the discs and point inwards from the edge of the discs, is disposed between the circular discs. When the separation device is in operation, the blade elements generate a counter-pressure on the stock/grinding body mixture, so that the grinding bodies are separated from the product due to the centrifugal force and the different specific density and are conveyed back into the interior.
European patent specification EP 0 627 262 B1 discloses a continuously operating agitator ball mill used for the fine and ultrafine grinding of a material. This agitator ball mill is provided with a cylindrical or conical grinding chamber serving to receive grinding bodies. Disposed at one end of the grinding chamber is a grinding stock inlet which emerges into the interior of the grinding chamber. Disposed at the other end of the grinding chamber is a grinding stock outlet which leads out of the interior. Furthermore, the agitator ball mill comprises agitator elements and an agitator moving coaxially with the grinding chamber axis for the purpose for moving the grinding bodies, wherein the agitator elements are constituted paddlewheel- or propeller-like and comprise a plurality of conveying elements. A circular disc is disposed respectively on both sides of the conveying elements, wherein at least one of the two discs comprises at least one central opening. The mixture formed by the grinding bodies and the stock to be ground can flow through the central opening. The agitator elements are constituted and dimensioned in such a way that, during the operation of the agitator ball mill, a part of the mixture continuously flows back radially inwards towards the central opening over the edge of the disc comprising the central opening. The mixture flows from there back into the intermediate space between the discs. A uniform axial distribution of the grinding bodies in the interior of the grinding chamber is thus obtained.
European patent EP 1 970 124 A2 discloses an agitator ball mill with a separation device for auxiliary grinding bodies, to which a preliminary classification device is assigned. This preliminary classification device comprises a cylinder which is provided with perforations. The perforations comprise circular holes or oval perforations or slots in the cylinder wall. A distance of 2 to 30 times the diameter of the perforations introduced in the cylinder exists between the separation device and the perforations in the cylinder.